Melanoma in patients with GATA2 deficiency

Cancer-associated fibroblasts contributed to hepatocellular carcinoma recurrence and metastasis via CD36-mediated fatty-acid metabolic reprogramming

Cancer-associated fibroblasts (CAFs) are the main components in the tumor microenvironment. Tumors activate fibroblasts from quiescent state into activated state by secreting cytokines, and activated CAFs may in turn promote tumor progression and metastasis. Therefore, studies targeting CAFs could enrich the therapeutic options for tumor treatment. In this study, we demonstrate that the content of lipid droplets and the expression of autophagosomes were higher in CAFs than in peri-tumor fibroblasts (PTFs), which was inhibited by 5-(tetradecyloxy)-2-furoic acid(TOFA). The expression of CD36 in CAFs was higher than that in PTFs at both mRNA and protein levels. Inhibition of CD36 activity using either the CD36 inhibitor SSO or siRNA had a significant negative impact on the proliferation and migration abilities of CAFs, which was associated with reduced levels of relevant activated genes (α-SMA, FAP, Vimentin) and cytokines (IL-6, TGF-β and VEGF-α). SSO also inhibited HCC growth and tumorigenesis in nude mice orthotopically implanted with CAFs and HCC cells. Our data further show that CD36+CAFs affected the expression of PD-1 in CTLs leading to CTL exhaustion, and that patients with high CD36 expression in CAFs were correlated with shorter overall survival (OS). Together, our data demonstrate that CAFs were active in lipid metabolism with increased lipid content and lipophagy activity. CD36 may play a key role in the regulation of the biological behaviors of CAFs, which may influence the proliferation and migration of tumor cells by reprograming the lipid metabolism in tumor cells. Thus, CD36 could be an effective therapeutic target for the treatment of HCC.

Melatonin suppresses tumor proliferation and metastasis by targeting GATA2 in endometrial cancer

Endometrial cancer (EC) is a reproductive system disease that occurs in perimenopausal and postmenopausal women. However, its etiology is unclear. Melatonin (MT) has been identified as a therapeutic agent for EC; however, its exact mechanism remains unclear. In the present study, we determined that GATA-binding protein 2 (GATA2) is expressed at low levels in EC and regulated by MT. MT upregulates the expression of GATA2 through MT receptor 1A (MTNR1A), whereas GATA2 can promote the expression of MTNR1A by binding to its promoter region. In addition, in vivo and in vitro experiments showed that MT inhibited the proliferation and metastasis of EC cells by upregulating GATA2 expression. The protein kinase B (AKT) pathway was also affected. In conclusion, these findings suggest that MT and GATA2 play significant roles in EC development.

Construction of Prognostic Risk Model of Patients with Skin Cutaneous Melanoma Based on TCGA-SKCM Methylation Cohort

Skin cutaneous melanoma (SKCM) is a common malignant skin cancer. Early diagnosis could effectively reduce SKCM patient's mortality to a large extent. We managed to construct a model to examine the prognosis of SKCM patients. The methylation-related data and clinical data of The Cancer Gene Atlas- (TCGA-) SKCM were downloaded from TCGA database. After preprocessing the methylation data, 21,861 prognosis-related methylated sites potentially associated with prognosis were obtained using the univariate Cox regression analysis and multivariate Cox regression analysis. Afterward, unsupervised clustering was used to divide the patients into 4 clusters, and weighted correlation network analysis (WGCNA) was applied to construct coexpression modules. By overlapping the CpG sites between the clusters and turquoise model, a prognostic model was established by LASSO Cox regression and multivariate Cox regression. It was found that 9 methylated sites included cg01447831, cg14845689, cg20895058, cg06506470, cg09558315, cg06373660, cg17737409, cg21577036, and cg22337438. After constructing the prognostic model, the performance of the model was validated by survival analysis and receiver operating characteristic (ROC) curve, and the independence of the model was verified by univariate and multivariate regression. It was represented that the prognostic model was reliable, and riskscore could be used as an independent prognostic factor in SKCM patients. At last, we combined clinical data and patient's riskscore to establish and testify the nomogram that could determine patient's prognosis. The results found that the reliability of the nomogram was relatively good. All in all, we constructed a prognostic model that could determine the prognosis of SKCM patients and screened 9 key methylated sites through analyzing data in TCGA-SKCM dataset. Finally, a prognostic nomogram was established combined with clinical diagnosed information and riskscore. The results are significant for improving the prognosis of SKCM patients in the future.

Melanoma susceptibility: an update on genetic and epigenetic findings

Malignant melanoma is one of the most highly ranked cancers in terms of years of life lost. Hereditary melanoma with its increased familial susceptibility is thought to affect up to 12% of all melanoma patients. In the past, only a few high-penetrance genes associated with familial melanoma, such as CDKN2A and CDK4, have been clinically tested. However, findings now indicate that melanoma is a cancer most likely to develop not only due to high-penetrance variants but also due to polygenic inheritance patterns, leaving no clear division between the hereditary and sporadic development of malignant melanoma. Various pathogenic low-penetrance variants were recently discovered through genome-wide association studies, and are now translated into polygenic risk scores. These can show superior sensitivity rates for the prediction of melanoma susceptibility and related mixed cancer syndromes than risk scores based on phenotypic traits of the patients, with odds ratios of up to 5.7 for patients in risk groups. In addition to describing genetic findings, we also review the first results of epigenetic research showing constitutional methylation changes that alter the susceptibility to cutaneous melanoma and its risk factors.

Nile Tilapia: A Model for Studying Teleost Color Patterns

The diverse color patterns of cichlid fishes play an important role in mate choice and speciation. Here we develop the Nile tilapia (Oreochromis niloticus) as a model system for studying the developmental genetics of cichlid color patterns. We identified 4 types of pigment cells: melanophores, xanthophores, iridophores and erythrophores, and characterized their first appearance in wild-type fish. We mutated 25 genes involved in melanogenesis, pteridine metabolism, and the carotenoid absorption and cleavage pathways. Among the 25 mutated genes, 13 genes had a phenotype in both the F0 and F2 generations. None of F1 heterozygotes had phenotype. By comparing the color pattern of our mutants with that of red tilapia (Oreochromis spp), a natural mutant produced during hybridization of tilapia species, we found that the pigmentation of the body and eye is controlled by different genes. Previously studied genes like mitf, kita/kitlga, pmel, tyrb, hps4, gch2, csf1ra, pax7b, and bco2b were proved to be of great significance for color patterning in tilapia. Our results suggested that tilapia, a fish with 4 types of pigment cells and a vertically barred wild-type color pattern, together with various natural and artificially induced color gene mutants, can serve as an excellent model system for study color patterning in vertebrates.

Germline Predisposition to Hematolymphoid Neoplasia

OBJECTIVES

The 2017 Workshop of the Society for Hematopathology/European Association for Haematopathology aimed to review clinical cases with germline predisposition to hematolymphoid neoplasms.

METHODS

The Workshop Panel reviewed 51 cases with germline mutations and rendered consensus diagnoses. Of these, six cases were presented at the meeting by the submitting pathologists.

RESULTS

The cases submitted to the session covering germline predisposition included 16 cases with germline GATA2 mutations, 10 cases with germline RUNX1 mutations, two cases with germline CEBPA mutations, two germline TP53 mutations, and one case of germline DDX41 mutation. The most common diagnoses were acute myeloid leukemia (15 cases) and myelodysplastic syndrome (MDS, 14 cases).

CONCLUSIONS

The majority of the submitted neoplasms occurring in patients with germline predisposition were myeloid neoplasms with germline mutations in GATA2 and RUNX1. The presence of a germline predisposition mutation is not sufficient for a diagnosis of a neoplasm until the appearance of standard diagnostic features of a hematolymphoid malignancy manifest: in general, the diagnostic criteria for neoplasms associated with germline predisposition disorders are the same as those for sporadic cases.

The Long Noncoding RNA UCA1 Negatively Regulates Melanogenesis in Melanocytes

The long noncoding RNA UCA1 was first discovered in bladder cancer and is known to regulate the proliferation and migration of melanoma. However, its role in melanogenesis is unclear. In this study, we aimed to explore the role and mechanism of UCA1 in melanogenesis. Our findings showed that the expression of UCA1 was negatively correlated with melanin content in melanocytes and pigmented nevus. Overexpression of UCA1 in melanocytes decreased melanin content and the expression of melanogenesis-related genes, whereas knockdown of UCA1 in melanocytes had the opposite effect. High-throughput sequencing revealed that microphthalmia-associated transcription factor (MITF), an important transcription factor affecting melanogenesis, was also negatively correlated with the expression of UCA1. Furthermore, the transcription factor CRE-binding protein (CREB), which promotes MITF expression, was negatively regulated by UCA1. The cAMP/protein kinase A (PKA), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) signaling pathways, which are upstream of the CREB/MITF/melanogenesis axis, were activated or inhibited in response to silencing or enhancing UCA1 expression, respectively. In addition, enhanced UCA1 expression downregulates the expression of melanogenesis-related genes induced by UVB in melanocytes. In conclusion, UCA1 may negatively regulate the CREB/MITF/melanogenesis axis through inhibiting the cAMP/PKA, ERK, and JNK signaling pathways in melanocytes. UCA1 may be a potential therapeutic target for the treatment of pigmented skin diseases.

CEBPA-mutated leukemia is sensitive to genetic and pharmacological targeting of the MLL1 complex

The gene encoding the transcription factor C/EBPα is mutated in 10-15% of acute myeloid leukemia (AML) patients. N-terminal CEBPA mutations cause ablation of full-length C/EBPα without affecting the expression of a shorter oncogenic isoform, termed p30. The mechanistic basis of p30-induced leukemogenesis is incompletely understood. Here, we demonstrate that the MLL1 histone-methyltransferase complex represents a critical actionable vulnerability in CEBPA-mutated AML. Oncogenic C/EBPα p30 and MLL1 show global co-localization on chromatin and p30 exhibits robust physical interaction with the MLL1 complex. CRISPR/Cas9-mediated mutagenesis of MLL1 results in proliferation arrest and myeloid differentiation in C/EBPα p30-expressing cells. In line, CEBPA-mutated hematopoietic progenitor cells are hypersensitive to pharmacological targeting of the MLL1 complex. Inhibitor treatment impairs proliferation and restores myeloid differentiation potential in mouse and human AML cells with CEBPA mutations. Finally, we identify the transcription factor GATA2 as a direct critical target of the p30-MLL1 interaction. Altogether, we show that C/EBPα p30 requires the MLL1 complex to regulate oncogenic gene expression and that CEBPA-mutated AML is hypersensitive to perturbation of the MLL1 complex. These findings identify the MLL1 complex as a potential therapeutic target in AML with CEBPA mutations.

Skin disorders are prominent features in primary immunodeficiency diseases: A systematic overview of current data

Primary immunodeficiency diseases (PIDs) are characterized by an increased risk of infections, autoimmunity, autoinflammation, malignancy, and allergic disorders. Skin disorders are also common clinical features in PIDs and may be among the presenting manifestations. Recognition of specific PID-associated skin conditions in combination with other clinical features as described in the currently used warning signs could raise suspicion of an underlying PID. We aimed to provide a systematically obtained overview of skin disorders and their prevalence in PIDs. Secondary, the prevalence of Staphylococcus (S.) aureus-associated skin disorders and atopy was reviewed, as these are the most prominent skin features in PIDs. A systematic search was performed in EMBASE, MEDLINE, Web of Science, Cochrane, and Google Scholar (up to May 9, 2018). All original observational and experimental human studies that address the presence of skin disorders in PIDs were selected. We rated study quality using the Institute of Health Economics Quality Appraisal Checklist for Case Series Studies. Sixty-seven articles (5030 patients) were included. Study quality ranged from 18.2% to 88.5%. A broad spectrum of skin disorders was reported in 30 PIDs, mostly in single studies with a low number of included patients. An overview of associated PIDs per skin disorder was generated. Data on S. aureus-associated skin disorders and atopy in PIDs were limited. In conclusion, skin disorders are prominent features in PIDs. Through clustering of PIDs per skin disorder, we provide a support tool to use in clinical practice that should raise awareness of PIDs based on presenting skin manifestations.